MYSTERIOUS ROUTER DEATH (for one of two printers)

Two printers hooked up to a Linksys RV082 10/100 8-Port VPN Router: an HP 4250, and an HP 2840. Last night, everything worked. This morning, the 2840 responded to nothing. Nothing at all. Spent several hours checking and rechecking connections. Still nothing. The 4250 continued to work just fine, and the 2840 just stared at us. Finally had the presence of mind to look more closely at the router, and I switched the two printer ports when I noticed that the light for Port 5 (the port for the 2840) was dark. The 2840 immediately started spitting out the test documents we'd been sending to it all day, and the 4250, now plugged into Port 6, stopped working. So: the router is the problem. Why is one of the port lights dark? I tried resetting it, but it didn't really respond. Does anybody know what's happening?